Lack of green space, abundant concrete, and building materials that trap heat all contribute to why cities are often as much as 10 degrees warmer than surrounding suburbs. Johns Hopkins earth and planetary sciences professor Dr. Ben Zaitchik talks with Stephanie Desmon about urban heat islands which disproportionately affect poorer and minority communities, why heat is known as “the silent killer,” and how investments in urban heat mitigation can help make neighborhoods stronger and safer.